Metamath Proof Explorer


Theorem elpmi

Description: A partial function is a function. (Contributed by Mario Carneiro, 15-Sep-2015)

Ref Expression
Assertion elpmi ⊢ F ∈ A ↑ 𝑝𝑚 B → F : dom ⁡ F ⟶ A ∧ dom ⁡ F ⊆ B

Proof

Step Hyp Ref Expression
1 n0i ⊢ F ∈ A ↑ 𝑝𝑚 B → ¬ A ↑ 𝑝𝑚 B = ∅
2 fnpm ⊢ ↑ 𝑝𝑚 Fn V × V
3 2 fndmi ⊢ dom ⁡ ↑ 𝑝𝑚 = V × V
4 3 ndmov ⊢ ¬ A ∈ V ∧ B ∈ V → A ↑ 𝑝𝑚 B = ∅
5 1 4 nsyl2 ⊢ F ∈ A ↑ 𝑝𝑚 B → A ∈ V ∧ B ∈ V
6 elpm2g ⊢ A ∈ V ∧ B ∈ V → F ∈ A ↑ 𝑝𝑚 B ↔ F : dom ⁡ F ⟶ A ∧ dom ⁡ F ⊆ B
7 5 6 syl ⊢ F ∈ A ↑ 𝑝𝑚 B → F ∈ A ↑ 𝑝𝑚 B ↔ F : dom ⁡ F ⟶ A ∧ dom ⁡ F ⊆ B
8 7 ibi ⊢ F ∈ A ↑ 𝑝𝑚 B → F : dom ⁡ F ⟶ A ∧ dom ⁡ F ⊆ B